Permission denied while trying to install opencv4nodejs in Ubuntu - node.js

Question

I was trying to install opencv4nodejs in Ubuntu-20.04 using the following command and my node version is v12.19.0
sudo npm i -g opencv4nodejs
But getting those errors
info install installing opencv version 3.4.6 into directory: /usr/lib/node_modules/opencv4nodejs/node_modules/opencv-build/opencv
ERR! Error: Command failed: mkdir -p opencv
mkdir: cannot create directory ‘opencv’: Permission denied
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! opencv-build#0.1.9 install: `node ./install.js`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the opencv-build#0.1.9 install script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! /root/.npm/_logs/2020-10-28T06_33_21_090Z-debug.log

Answer 1

Running NPM install with sudo might be causing a permissions problem. You could try completely removing the node_modules directory and re-running NPM install it without sudo.
Also make sure you have permission to write to the directory you're installing in?
If it still doesn't work please follow this:
sudo npm install -g opencv4nodejs --unsafe-perm=true --allow-root

Answer 2

This is complete guide to install opencv4nodejs to Linux OS or Raspberry pi (Raspberry Pi OS )
configuration
01- sudo raspi-config expand file system // this is for raspberry pi
After Reboot (sudo reboot now)
02- df -h (To check expand file system)
03- sudo apt-get update && sudo apt-get upgrade -y
04- sudo passwd root // set up your root password
Reboot
To Install NodeJS
01- sudo apt-get install git -y
02- curl -sL https://deb.nodesource.com/setup_12.x | sudo -E bash - // replase 12 with latest nodejs (LTS) version
03- sudo apt-get install nodejs -y
04- sudo apt-get install gcc g++ make
To Install opencv4nodejs
01. sudo apt-get install cmake -y
02. sudo npm install -g node-gyp
I am using this steps for raspberry pi os
03. sudo nano /etc/dphys-swapfile
(Increase the CONF_SWAPSIZE from 100 to 1024)
sudo /etc/init.d/dphys-swapfile stop
sudo /etc/init.d/dphys-swapfile start
cd to home dir..
04. mkdir opencv
05. cd opencv
06. sudo npm init -y
07. su
// Enter your setup root password
08. sudo npm install --save opencv4nodejs
09. sudo nano /etc/dphys-swapfile
(Set the CONF_SWAPSIZE back to 100)
In index.js and node_modules in same folder
const cv = require("opencv4nodejs");
In index.js and node_modules in not in same folder
const cv = require("path/opencv/node_modules/opencv4nodejs");
! you don't need to install opencv4nodejs for each folders
You can simply call that above way
Hope guys you can understand it...
Any questions feel free to ask...
Thank you